I've found a stud conversion kit on eBay, it's basically a set of studs, 12x1.5 on both ends. About 10mm of thread, and then maybe 35-45mm on the other end. They appear to just screw in to your hub, probably would help to use some Loctite. But has anyone actually had much experience with these? I'm just thinking it seems a little suss, normal studs have the small backing piece, they physically can't come out, where as these just wind in.

The other option I know a couple people have used is to get BMW bolts, or aftermarket bolts off eBay, but all the bolts I've been able to find have a taper, where the wheels I have to go on don't. You can buy extended shank wheel NUTS at pretty much every auto shop here, but I haven't been able to ind any BOLTS that are a similar design.

Yeah, sorry about that.. Without putting pictures in it's hard to explain and I don't have access to a computer at the moment.

Car in question is a 1981 Mazda CB 626, but as far as I'm aware, most old Mazda's have similar bolts instead of nuts. Why I put Mazda in the title.

The item I'm talking about converts the hubs to studs and nuts, rather than bolts. I would end up using the nut you've mentioned, as I have on my other car, which has an extended shank, like you say, to grab more thread down into the wheel.

I've already found the kit, I don't need anything custom, I'm just wondering if anyone can shed some light on them for myself and others, as I've never dealt with them and they don't seem particularly safe, just being wind in studs. It seems like they could possibly wind themselves out.

It's been done before, very popular with VW guys. There are stories of them coming loose!

You can also drill out the threads and get the "knock in" studs, but it requires taking the half shafts out of the diff. Do the discs come free from the hub on the 626? On the 323 they were part of the hub, so you couldn't hit them through from the back...

I'm not sure man, I haven't looked at the rotors yet. Only to check the brakes, didn't pay much attention to how they'd come off. I've found a lot of similar things to the 323 though, so I reckon they'd be the same. Probably the same brakes.

You've heard stories of the wind in ones coming out?!?? How badly did this story go...? not sounding too good..

The ones I found are only about $40 shipped. I mean, I don't see that there'd be much variation whether you pay $200 or $40, they'd have to be a certain tensile strength to hold the wheels on, no matter how much you pay.

Knock in studs seem loads better, but so much messing around, I'm not up for it, if there's an easier way.

I bought them off a guy real cheap, he said he had them on an RX3, I think. Not sure how he'd fastened them to the hubs, although there is a bit of wear right on the inside of the holes, so probably just some lug bolts like you got for the 323.

I'm thinking these studs seem the best, because then I can just get extended lug nuts that will fit the wheels no problem. Only two issues with this plan, and they are reasonably big..

1) you said you've heard of the studs coming out. That is a big worry, ahahah.

2) the extended lug nuts have a closed end. The studs have an Allen bolt key thing cut out of the end, so you can do them up easily. That would also come in very handy if, say, when you undo one of the nuts, the stud comes with it.

Actually, I suppose if that happened, you'd just take the nut and stud out together and then the stud would just wind out. Not so much of an issue after all.

I think I'll go with these studs, just make sure I Loctite the hell out of them.